{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://thinkloom.app/schemas/provenance/1.0/text-fragment-reference.schema.json",
  "title": "Text fragment reference",
  "description": "Stable revision-bound text range with an explicit coordinate system.",
  "type": "object",
  "properties": {
    "schema_version": {
      "const": "1.0"
    },
    "document_revision_id": {
      "type": "string",
      "pattern": "^revision_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "coordinate_system": {
      "enum": [
        "utf8_byte",
        "unicode_scalar",
        "utf16_code_unit",
        "editor_position"
      ]
    },
    "start": {
      "type": "integer",
      "minimum": 0
    },
    "end": {
      "type": "integer",
      "minimum": 0
    },
    "preimage_sha256": {
      "type": "string",
      "pattern": "^sha256:[a-f0-9]{64}$"
    },
    "text_fragment_id": {
      "anyOf": [
        {
          "type": "string",
          "pattern": "^fragment_[0-9A-HJKMNP-TV-Z]{26}$"
        },
        {
          "type": "null"
        }
      ]
    }
  },
  "required": [
    "schema_version",
    "document_revision_id",
    "coordinate_system",
    "start",
    "end",
    "preimage_sha256",
    "text_fragment_id"
  ],
  "additionalProperties": false,
  "examples": [
    {
      "schema_version": "1.0",
      "document_revision_id": "revision_01J0000000000000000000000A",
      "coordinate_system": "utf8_byte",
      "start": 0,
      "end": 12,
      "preimage_sha256": "sha256:1111111111111111111111111111111111111111111111111111111111111111",
      "text_fragment_id": "fragment_01J0000000000000000000000C"
    }
  ]
}